The big physics news of the week last week came while I was in transit on Wednesday: The MiniBooNE (the odd capitalization is because it’s sort of an acronym) neutrino experiment released their first results on the neutrino oscillation studies they’ve been doing, and found, well, nothing new. In contrast to a previous experiment that hinted at the possible existence of a fourth type of neutrinos, the MiniBooNE results were entirely consistent with having only the three previously known types. There’s a news article here, and one of the MiniBooNE experimenters did a excellent guest post explaining the results at Cosmic Variance.

I don’t have much to say about the results themselves because, well, I’m not actually a neutrino physicist. One thing about this that’s really interesting, though, is that it’s yet another “success” for the Standard Model of particle physics.

It occurs to me that the Standard Model is in kind of a unique position among scinetific theories. I know of lots of examples of theories that everybody thought were right that turned out to be wrong, and there are plenty of examples of theories that at least some people think are right but that they can’t prove right. The Standard Model is the only theory I can think of that everybody knows is wrong, but nobody can prove is wrong.

OK, “wrong” may be a little too strong– “incomplete” is probably a better word. The Standard Model consists of a set of twelve material particles: six quarks (up, down, strange, charm, top, and bottom) and six leptons (electron, muon, tau, and electron, muon and tau neutrinos) with their associated antiparticles. It also includes four forces: gravity, electromagnetism, the strong nuclear force, and the weak nuclear force, plus their associated force carriers. Taken together, these particles and forces describe everything about the structure and organization of ordinary matter.

The problem is, they don’t explain everything. Most of the universe is made up of “dark matter” that we see only indirectly through its gravitational interactions with stars and galaxies. For various reasons, we know that this matter, whatever it is, can’t be made up of quarks, but beyond that, we have no idea what it is. There are lots of proposals of different sorts of particles not included in the Standard Model that could account for this extra mass, but nobody has ever conclusively seen one.

There’s also the question of mass: The Standard Model enumerates the particles and their masses, but doesn’t say why they have those masses. There’s a proposed mechanism by which fundamental particles could acquire their masses from interactions with another sort of particle– the interaction is called the “Higgs mechanism” and the particles are “Higgs bosons,” and there ought to be one for every type of material particle. Nobody has ever seen conclusive evidence of a Higgs boson, though, despite many active searches for them.

This is really a strange and awkward position to be in. The Standard Model works extremely well for those things that it describes, but we know it can’t be the whole story. And yet, every attempt to find physics beyond the Standard Model has come up empty. Nobody has yet found a particle or force that isn’t accounted for in the theory, despite a couple of decades’ worth of searching. In a certain sense, it’s a theory that works too well. We’ve got excellent indirect evidence that says it can’t be the whole story, but we can’t find any direct evidence of anything that doesn’t fit the theory.

It’s sort of like being in the early stages of one of those old Infocom text adventure games. We’ve explored all the obvious rooms, and picked up all the obvious items, but we haven’t really gotten anywhere. There’s got to be more to the game, because it takes up a lot of disk space, but we can’t find any way to get into any of the other rooms even though we know they have to be there…

I’m not sure what the particle physics analogue of being eaten by a grue is, though– loss of funding, maybe?

Comments

Great post, it is puzzling, and maybe a little worrisome, how well the SM works. Hopefully news will come at the LHC.

Small correction, the standard model has a single Higgs boson (some extensions have a couple), and all particles presumably get their masses through their interactions to that boson. This was a little ambiguous the way phrased.

To use an Infocom analogy, the Standard Model seems to me rather like the thing your aunt gave you but you don’t know what it is from the Hitch-hiker’s Guide game – it takes whatever you can throw at it, and you can’t get rid of it.

PS. Just for Jeff, some Infocom links:

Flash version of H2G2 from the BBC, with illustrations by, among others, Rod Lord (who did the hand-animated TV series graphics).

We build LEP in CERN. It’s hugely expensive, but that’s the cost of doing high-energy physics nowadays. (The energies have gotten really high.) The successor to LEP is the ILC (International Linear Collider), which will be that much more expensive.

But LEP doesn’t find the Higgs boson, nor does it find supersymmetry. It does find all sorts of interesting physics, much as the colliders now are, but it’s the sort of stuff only really of interest to other particle physicists, and not the sort of stuff of interest to somebody watching a Nova special.

No Higgs boson, no supersymmetry, and it will become an EXTREMELY hard sell to tell people that we need spend even more money to go to the next energy frontier.

Nuclear and particle physics had a watershed century in the 20th century. Every time we went to a new energy, we found new stuff, and cool new stuff. Things were expanding all the time. There were dark periods, sure, such as when we had this zoo of particles without a great way to unify them, but the eightfold way and the quark model did nice things to all of that. But the experiments were always finding new stuff.

If we don’t find something big and new — something like supersymmetry and “dark matter” LSP, or the Higgs boson, or, even better, something unexpected — at LEP, it’s going to be a long time before we have the stomach to look harder. Maybe the next energy threshold is what’s needed, but without some payoff at each step, it’s hard to make the next step.

That’s the grue.

Oh, and text adventures are a lot of fun!

sometimes I wonder why I make long comments like this in others’ blogs instead of just making it a post on my own blog.

I think that string theory might provide the answer to dark matter. I think that gravity is just as strong as the electrical forces, but some is projected out of our Brane and either into someone elses brane, (I am the dark matter in someone elses universe!) or back into our own.

“No Higgs boson, no supersymmetry, and it will become an EXTREMELY hard sell to tell people that we need spend even more money to go to the next energy frontier.”

No Higgs boson and no other new physics would mean our understanding of quantum mechanics is fundamentally wrong (unitarity would be violated). I don’t have any idea what that would mean for funding for future experiments. Of course, it won’t happen, because unitarity breakdown is crazy. So there will be (at least) a Higgs.

Same point to Rob as onymous, though I can’t be sure since I’m not a physicist. This exchange near the end of The Newtonian Legacy made me hope that the LHC will find something interesting, whatever it is:

”No, actually, this experiment is the Holy Grail of science in that it is a ’no lose’ machine! If you take our theories of particles and omit the Higgs, funny stuff happens. In particular if you scatter W particles, the ones responsible for the weak force, then the chance of them interacting grows with energy. Eventually the probability of interaction becomes bigger than one!”
“What does that mean?”
“It means the theory is rubbish! Something has to happen that’s new. The LHC will be able to probe this behaviour for sure. So we’re guaranteed to find another part of the puzzle.”

Einstein’s Nemesis: DI Herculis Apsidal motion solution
It is not about just throwing relativity theory but throwing relativity theory with NASA Astrophysicists Attached to it.
Abstract: This is the Solution to the “quarter of a century” motion puzzle that Einstein and all other 100,000 space-time physicists and Astrophysicists could not solve by space-time physics or any other said or published physics including 109 years of Noble Prize winner physics and 400 years of Astro-physics and dedicated to Dr Edward Guinan and Dr Frank Maloney of Villanova University who posted this motion puzzle in 1985 as not solvable by space-time physics and in “Apparent” inconsistency with General relativity theory and started the binary stars collections with motion that can not be explained by space-time physics or any said or published physics. This motion puzzle is posted on Smithsonian-NASA website SAO/NASA.

Introduction Time is not a structure like space- to scientifically accept space- to imaginary time – back to space jumping continuum told by Einstein and taught by MIT Harvard Cal-Tech Stanford NASA and all other space-time physics departments regardless what the 100,000 Space-time Physicists have/had said about it because space-time physics is not good enough to solve the simplest problem in physics introduced here and solved.

Universal Mechanics Solution:

For 350 years Physicists Astronomers and Mathematicians missed Kepler’s time dependent equation introduced here and transformed Newton’s equation into a time dependent Newton’s equation and together these two equations explain Quantum – Relativistic effects; it combines classical mechanics and quantum mechanics into one mechanics and explains “relativistic” effects as the difference between time dependent measurements and time independent measurements of moving objects and in practice it amounts to “Visual” effects.

All there is in the Universe is objects of mass m moving in space (x, y, z) at a location
r = r (x, y, z). The state of any object in the Universe can be expressed as the product

Books

You've read the blog, now try the books:

Eureka: Discovering Your Inner Scientist will be published in December 2014 by Basic Books. "This fun, diverse, and accessible look at how science works will convert even the biggest science phobe." --Publishers Weekly (starred review) "In writing that is welcoming but not overly bouncy, persuasive in a careful way but also enticing, Orzel reveals the “process of looking at the world, figuring out how things work, testing that knowledge, and sharing it with others.”...With an easy hand, Orzel ties together card games with communicating in the laboratory; playing sports and learning how to test and refine; the details of some hard science—Rutherford’s gold foil, Cavendish’s lamps and magnets—and entertaining stories that disclose the process that leads from observation to colorful narrative." --Kirkus ReviewsGoogle+

How to Teach Relativity to Your Dog is published by Basic Books. "“Unlike quantum physics, which remains bizarre even to experts, much of relativity makes sense. Thus, Einstein’s special relativity merely states that the laws of physics and the speed of light are identical for all observers in smooth motion. This sounds trivial but leads to weird if delightfully comprehensible phenomena, provided someone like Orzel delivers a clear explanation of why.” --Kirkus Reviews "Bravo to both man and dog." The New York Times.

How to Teach Physics to Your Dog is published by Scribner. "It's hard to imagine a better way for the mathematically and scientifically challenged, in particular, to grasp basic quantum physics." -- Booklist "Chad Orzel's How to Teach Physics to Your Dog is an absolutely delightful book on many axes: first, its subject matter, quantum physics, is arguably the most mind-bending scientific subject we have; second, the device of the book -- a quantum physicist, Orzel, explains quantum physics to Emmy, his cheeky German shepherd -- is a hoot, and has the singular advantage of making the mind-bending a little less traumatic when the going gets tough (quantum physics has a certain irreducible complexity that precludes an easy understanding of its implications); finally, third, it is extremely well-written, combining a scientist's rigor and accuracy with a natural raconteur's storytelling skill." -- BoingBoing